1. Technical Field
The present disclosure relates generally to light emitting diode (LED) packages, and more particularly to an LED package with improved light emitting efficiency by transmitting an excited light from an LED chip and absorbing the excited light in a phosphor and emitting a wavelength conversion light obtained by converting a wavelength of the excited light.
2. Description of Related Art
LEDs are solid state light emitting devices formed of semiconductors, which are more stable and reliable than other conventional light sources such as incandescent bulbs. Such LEDs emit light close to approximately single color light, which is different from light having a wide light emitting spectrum from incandescent bulbs. Recently, LEDs capable of emitting white light have been developed. A method of obtaining a white LED package is encapsulating a blue LED chip with a phosphor layer where yellow phosphors are scattered. When blue light is emitted from the blue LED chip, yellow light is emitted from the yellow phosphors absorbing the blue light from the blue LED chip, thereby outputting white light by mixing two types of light whose wavelengths are different from each other.
Since a refraction index of the phosphor layer is different from that of the air outside of the LED package, light emitted from the blue LED chip is capable of occurring total internal reflection at an interface between the phosphor layer and the air, and cannot be transmitted outside, resulting in a lower light emitting efficiency.
What is needed therefore is an LED package having an improved light emitting efficiency.